Neuropeptidomics of Clock-to-Clock Coupling

描述（由申请人提供）：生物学中一个未解决的中心问题是，什么协调生物体的生物钟？大脑中的中央昼夜节律钟、视交叉上核（SCN）和其他细胞和组织中的昼夜节律钟之间的协调丧失已经涉及导致睡眠障碍的系统病理。这项发现提案的目标是确定耦合SCN和[神经胶质]生物钟的肽。对隔离培养的外周组织的研究表明，在SCN不存在的情况下，细胞节律继续，但在不同组织中，包括脑、肝、肺、肌肉、肾、尾[和脾]，相位和周期特性发生变化。在解耦的情况下，各种组织功能失去时间相干性以及与睡眠和觉醒的日常周期的适当对准。人们对生物体生物钟的耦合因素知之甚少，除了扩散因素足以影响许多生物钟之外。发现将SCN与其他生物钟（大脑和身体中的生物钟）联系起来的耦合因素已经被证明是困难的。我们提出了一项研究，应用先进的分析肽组技术在微米尺度上加上功能测定肽的能力，以恢复时钟到时钟的协调，一种创新的方法。我们的目标是：1）定义和表征SCN驱动的[神经胶质]节律同步化的诱导，2）通过肽组分析鉴定释放的候选偶联肽，3）确定从SCN释放的候选偶联肽用于诱导[神经胶质]时钟同步节律的必要性/充分性，以及4）表征和评估候选偶联肽。这些目标的成功完成将使我们在动物模型中测试偶联。内部时钟之间失去同步对健康和长寿是不适应的。目前还没有更好地同步或增强内部时钟耦合的方法。识别有效耦合昼夜节律的信号将在治疗代谢综合征，肥胖，心血管压力和衰老的生理衰退方面具有重要价值，所有这些都表现为睡眠模式紊乱，每年影响超过1000万美国人。然而，为了实现治疗潜力，SCN与其他生物钟接合的信号必须被识别并置于时间背景中。公共卫生相关性：该提案旨在确定在整个睡眠-觉醒周期中提供身体功能中昼夜节律整合的神经肽。大脑中的中央昼夜节律钟、视交叉上核（SCN）和其他细胞和组织中的昼夜节律钟之间的协调性丧失已经与导致睡眠障碍的系统病理学有关，并且对健康和长寿是不适应的。识别有效耦合整个身体的昼夜节律的信号将在治疗代谢综合征，肥胖，心血管压力和衰老的生理衰退方面具有重要价值，所有这些都表现为每年影响超过1000万美国人的睡眠模式紊乱;然而，为了实现治疗潜力，SCN与其他昼夜节律钟接合的信号必须被识别并置于时间背景中。

Description (provided by applicant): A central unsolved question in biology is, What coordinates an organism's circadian clocks? Loss of coordination between the central circadian clock in the brain, the suprachiasmatic nucleus (SCN), and circadian clocks in other cells and tissues has been implicated in systems pathologies that lead to sleep disorders. The goal of this discovery proposal is to identify peptides that couple the SCN and [glial] circadian clocks. Studies of peripheral tissues cultured in isolation have revealed that in the SCN's absence, cellular rhythms continue but phase and period properties change in diverse tissues, including brain, liver, lung, muscle, kidney, tail [and spleen]. With decoupling, the various tissue functions lose temporal coherence as well as appropriate alignment to the daily cycle of sleep and wakefulness. Little is known about what couples an organism's circadian clocks, except that diffusible factors are sufficient to entrain many. Discovering coupling factors that communicate time-of-day from SCN to other circadian clocks [in brain and body] has proven difficult. We propose a study applying advanced analytical peptidomic techniques on a micrometer scale coupled with functional determinations of the ability of peptides to restore clock-to-clock coordination, an innovative approach. We aim to: 1) define and characterize induction of SCN-driven synchronization of [glia] rhythms, 2) identify released candidate coupling peptides by peptidomic analysis, 3) determine the necessity/sufficiency of candidate coupling peptides released from the SCN for inducing synchronous rhythms of [glia] clocks, and 4) characterize and evaluate candidate coupling peptides. Successful completion of these aims will poise us for testing coupling in animal models. Loss of synchrony among internal clocks is maladaptive for health and longevity. There are no current approaches to better synchronize or enhance coupling of the internal clocks. Identifying signals that effectively couple circadian rhythms will have major value in treatment of metabolic syndrome, obesity, cardiovascular stress, and physiological decline with aging, all of which manifest with disordered sleep patterns that affect more than 10 million Americans each year. However, to realize therapeutic potential, signals by which the SCN engages other circadian clocks must be identified and placed in temporal context. PUBLIC HEALTH RELEVANCE: This proposal seeks to identify neuropeptides that provide integration of circadian rhythms in body function across the sleep-wake cycle. Loss of coordination between the central circadian clock in the brain, the suprachiasmatic nucleus (SCN), and circadian clocks in other cells and tissues has been implicated in systems pathologies that lead to sleep disorders, and is maladaptive for health and longevity. Identifying signals that effectively couple circadian rhythms throughout the body will have major value in treatment of metabolic syndrome, obesity, cardiovascular stress, and physiological decline with aging, all of which manifest with disordered sleep patterns that affect more than 10 million Americans each year; however, to realize therapeutic potential, signals by which the SCN engages other circadian clocks must be identified and placed in a temporal context.